Engineering antiphase boundaries in epitaxial SrTiO3 to achieve forming free memristive devices

We here present a method to engineer Ruddlesden-Popper-type antiphase boundaries in stoichiometric homoepitaxial SrTiO3 thin films. This is achieved by using a substrate with an intentionally high miscut, which stabilizes the growth of additional SrO at the bottom interface. We prove the success of this strategy utilizing transmission electron microscopy. We find that these antiphase boundaries significantly influence the resistive switching properties. In particular, devices based on SrTiO3 thin films with intentionally induced antiphase boundaries do not require a forming step, which is ascribed to the existence of preformed filaments.